a bank account pays 3% interest. Suppose you invest $2000 in such an account.
Let a(n) be the amount in the account after n years. So a1=2000+0.03*2000=2060 and a2=2060+0.03*2060=2121.80. Find a3 and a4?

Is this sequence an arithmetic sequence, geometric sequence or neither? and why?

Find a10

May 31st 2008, 08:31 PM

james21

well i know it is not arithmetic but i'm not so sure about what exactly, and is this simple or compound interest

Jun 1st 2008, 12:35 AM

Moo

Hello,

Quote:

Originally Posted by gumi

a bank account pays 3% interest. Suppose you invest $2000 in such an account.
Let a(n) be the amount in the account after n years. So a1=2000+0.03*2000=2060 and a2=2060+0.03*2060=2121.80. Find a3 and a4?

Is this sequence an arithmetic sequence, geometric sequence or neither? and why?

It's compound interest since you're taking 3% of whatever the last total is and not just 3% of the initial amount
a3 is easy: 2121.80+0.03*2121.80 = 2185.45
You could just write it as 2121.80*1.03, or even